Fresh crater on the southwest rim of Metius B crater. LROC NAC image width is 740 meters.

Impacts at all scales dominate the lunar surface. This is a relatively small (440 m diameter) unnamed crater on the southwest rim of Metius B, which itself is a 14 km diameter crater on the floor of Metius, an 88 km diameter crater in the southeast highlands on the lunar nearside. Some post-impact modifications to this crater are readily apparent. Although the crater itself is circular, you can see that the materials inside the crater slumped towards the downslope side of the crater following the impact. There are also numerous boulder trails emanating from around this very fresh crater, created when the rocks strewn outwards by this impact event landed on the slope and began rolling towards the bottom of Metius B.

Even though the Moon may not seem like a terribly dynamic environment, in actuality impacts still occur on a fairly regular basis. One of the critical goals of the LROC scientific investigation is to provide the necessary information to quantify the recent impact rate, providing a key data point for designers of future lunar habitats.

NASA's Goddard Space Flight Center built and manages the mission for the Exploration Systems Mission Directorate at NASA Headquarters in Washington. The Lunar Reconnaissance Orbiter Camera was designed to acquire data for landing site certification and to conduct polar illumination studies and global mapping. Operated by Arizona State University, the LROC facility is part of the School of Earth and Space Exploration (SESE). LROC consists of a pair of narrow-angle cameras (NAC) and a single wide-angle camera (WAC). The mission is expected to return over 70 terabytes of image data.